mojoPortal is committed to being a cross-platform web solution and the ability to run on Linux using Mono has been a primary driver for the project since its inception. In fact for a long time mojoPortal.com was hosted on Mono. Then when 2.0 .NET came out we knew it was important to start taking advantage of all the great improvements of 2.0 .NET with mojoPortal, but that it would take a while for the Mono project to catch up on its 2.0 implementation. So we split the 2.x version of mojoPortal to a new branch and maintained the 1.x version for Mono.
As of Mono version 1.2.6, the 2.0 .NET version of mojoPortal is working reasonably well, with the exception of WebParts which are not yet implemented in Mono. So now we have retired the 1.x version of mojoPortal and are back to one code base for all platforms.
WebParts are excluded from the build we provide for Mono until this gets implemented in Mono.
The only other siginificant issue is the lack of support for CSSControlAdapters which means on Mono the menu and treeview render as tables whereas on Windows they render as ul li elements. Therefore the styles are not right on Mono for the menu because the css is setup for ul li.
If you want to help with testing or developing on Linux see the documentation here:
http://www.mojoportal.com/developmentonlinux.aspx
You'll need a GNU/Linux distro intalled, I recommend OpenSuSE, you'll need Mono and MonoDevelop 0.17 or higher.
Any help reporting or documenting bugs that we can report to the Mono team is greatly appreciated.
If you've never tried using Mono to run ASP.NET on Linux, I highly recommend it! The first time you see your own application actually running on Linux it seems like magic. Its fairly easy to setup your own machine for Mono, or you can get the VMWare image from here. A whole new universe where you can use your .NET skills is waiting.